The present invention relates to a system which deals with graphic information and which is utilized for computer-aided design (CAD), etc. More particularly, it relates to a drawing information processing method and system which are applicable to the design and production of a product and also to the transfer of design information to a production engineer.
In the design of a machine or the like, the model of graphic information is utilized for expressing the object to-be-designed. In the past, an object as shown in FIG. 2 by way of example was usually dealt with in terms of a two dimensional drawing as shown in FIG. 3. Recently, such objects are designed using computer systems. In such a system, the object is expressed, not only as a two-dimensional graphic, but also as a three-dimensional graphic. Moreover, the expression of the object to-be-designed is not restricted to the form thereof, but sometimes contains graphic items other than the form, such as dimensions (namely, lengths) and a reference line, or information items given by a numerical value and characters, such as weight, material and fabricating method.
In the areas of design and production, design information, etc., are transferred by a method as stated below.
The method is as illustrated in FIG. 15, and uses a database which is accessible by both an engineer in charge of design and an engineer in charge of production. With this method, the design engineer saves the data of an object to-be-designed in the database, and the production engineer refers to the saved data. If necessary, the production engineer can also alter the data. According to this method, the design engineer and the production engineer need not possess the data separately. In addition, data on a display method can be dealt with as belonging to the data object to-be-designed, and the information itself, which is delivered from the design engineer to the production engineer, is verified by the design engineer.
Two or more CAD systems connected by communication modules, for example, are used in the transfer of the design information as stated above. In the CAD systems, the data of the object to-be-designed and the data of the display method held in correspondence therewith are dealt with.
In general, design information is transferred from a design department to a production department. Information which is delivered from a design engineer to a production engineer is not of only one type for one product. The information contains, at least, information for fabricating parts and information for assembling the parts. Besides, appropriate display methods are existent for the respective information items. In other words, the method of display to be referred to is not the same for all the parts which constitute the object or product. Regarding the object shown in FIG. 2 by way of example, the information of an assembled state displayed in directions and configurations as shown in FIG. 3 is appropriate for assembling the object, and information items for displaying individual parts are appropriate for machining the parts. Moreover, since the constituent parts are of one set in themselves, the data items of the parts shown in individual drawings must be one set of data in order to keep the data consistent.
In this regard, with the prior-art method, even when the observer requires information items displayed in a plurality of aspects, only the data of one type of display method can be saved for the data of one object. By way of example, in a case where the data of the display method corresponding to FIG. 3 is saved in association with the data of the object, the data items of display methods corresponding to part drawings cannot be saved in association with the data of the object. On the other hand, in a case where the data of a display method corresponding to the part drawing of a specified part is saved, the data items of display methods corresponding to the drawing of the whole object and the part drawing of another part cannot be saved. Accordingly, even when the production engineer requires a plurality of types of information, for example, the information items corresponding to the part drawings and the information corresponding to the assembly drawing, only the data of one type of display method can be dealt with for the data of one object to-be-designed. Consequently, only the data of one type of display method can be delivered from the design engineer to the production engineer.
Therefore, when someone, for example the production engineer, wants to refer to a display method for which no display method data exists, the display method must be designated individually. Such an expedient becomes as illustrated in FIG. 4 in terms of a model. As seen from the figure, the display method is designated twice. This leads to the problem that the expedient expends labor and necessitates wasteful operations.
Another expedient is sometimes employed wherein the data of the object is copied and wherein the data items of different display methods are saved as belonging to the respective object data items. This expedient becomes as illustrated in FIG. 4 in terms of a model. Herein, a plurality of object data items are existent, which incurs the problems of increase in the quantity of data and complicacy in the management of the data. A technique for the management is, for example, an expedient proposed in Japanese Patent Application Laid-open No. 243568/1986. This technique, however, has the problem that the alterations of the data, etc., cannot be flexibly coped with. More specifically, in the case of altering the data, all the data items need to be altered, resulting in the problem that the alterations are laborious. Besides, some of the plurality of data items might fail to be altered, resulting in the disadvantage that it is difficult to keep the data items consistent on account the different versions which exist.